Integral crankcase and gearcase assembly for an internal combustion engine



P 1956 w A. WISEMAN 2,764,143

INTEGRAL CRANNCASE AND GEARCASE ASSEMBLY FOR AN INTERNAL COMBUSTIONENGINE Filed April 12, 1954 3 Sheets-Sheet l INV EN TOR. M/fimr J2M56070 Eepf. 25, 1956 Filed April 12, 1954 Ila A. WISEMAN INTEGRALCRANKCASE AND GEARCASE ASSEMBLY FOR AN INTERNAL COMBUSTION ENGINE 3Sheds-Sheet 2 INIfEN TOR. Msemmw 1956 A. WISEMAN 2,764,143

INTEGRAL CRANKCASE AND GEARCASE ASSEMBLY FOR AN INTERNAL COMBUSTIONENGINE Filed April 12, 1954 3 Sheets-Sheet 3 25 Jim INVENTOR. dull/raml4. dzlllseman Unite tates 2,764,143 Patented Sept. 25, 1956 INTEGRALCRANKCASE AND GEARCASE AS- FtDR AN INTERNAL COMBUSTION William A.Wisernan, Muskcgon, Mich, assignor to Continental Motors Corporation,Detroit, Mich, a corporation of Virginia Application April 12, 1954,Serial No. 422,460 9 Claims. (Cl. 123-495) My invention relates tointernal combustion engines for aircraft and more particularly to aspecially constructed integral crankcase and gear case assemblytherefor.

compactness of engine construction is of vital importance in aircraftengines, and many design changes have been incorporated from time totime in order to facilitate structural compactness and to minimize theoverall weight of said engines. The assignee company initiated thepresent trend in aircraft engines, which embody horizontally opposedcylinders, and which are generally used for powering various types ofprivate planes. The crankcase and gear case for these power plants haveundergone many changes and refinements in the past twenty-five years,since they were first introduced to the trade, but in all that time ithas not been deemed feasible to incorporate an integral structure.

It is an object of the present invention to further refine and improveon the manufacture of aircraft engines, to make same more compact andlighter in weight, by constructing an integral crankcase and gear caseassembly embodying improved constructional details which facilitateassembly and make such design practical from the point of view ofmanufacturing and servicing.

Further objects of my invention will be more apparent as the descriptionprogresses, pertaining to the many complex details which make thepresent design practical and economically feasible.

For a more detailed understanding of my invention, reference may be hadto the accompanying drawings illustrating a preferred embodiment of myinvention in which like characters refer to like parts or structuralelements throughout the several views, and in which Fig. l is a planelevational view of a multi-cylinder, horizontal opposed aircraftinternal combustion engine embodying my improved integral crankcase andgear case assembly.

Fig. 2 is a rear elevational view of the gear case end of said crankcaseand gear case assembly with the engine cylinders, crankshaft and engineaccessories removed from the assembly.

Fig. 3 is a fragmentary detailed horizontal sectional view taken on theline 3-3 of Fig. 2, and

Fig, 4 is a fragmentary detailed vertical section taken on the line 4-4of Fig. 2.

The aircraft engine, with which my invention is practicularly related,comprises in general a crankcase 10, a gear case 11, engine cylinders12, an oil cooler 14, a crankshaft l5 and various engine accessoriessuch as a starter 16, a generator 17, and magnetos 18. It may beobserved that the engine cylinders are disposed in opposed relation in acommon horizontal engine plane, and each bank of cylinders comprise twoor more aligned cylinders directly attached to and supported by theengine crankcase 10.

The crankcase and gear case assembly comprises a pair of integral casingmembers each casing member forming substantially one half an integralcrankcase and gear case structure. Such casing members are generallyL-shaped in side elevation, the longer arms thereof forming thecrankcase portions 10a and 10b, and the shorter of said two arms formingthe gear case portions 11a and 11b. Thus 10a and 11a are integral andlikewise 10b and 1112 are integral one with the other. These casingshave front end walls 10c, rear walls 110 and an intermediate wallportion 9 separating the gear case proper from the crankcase. It isfurther noted that gear case portions 11a and 111) project upwardlybeyond the topmost part of said crankcase portions and 10b (see Fig. 4),and such upwardly projecting portions carry means 25 for supportingengine accessories such as magnetos L8. Said accessories may besupported on both front and rear walls of said gear case structure.

The two half casings 10a1la and 10b-11b are substantially symmetricaland do complement each other to complete the assembly. These halfcasings have abutting vertical faces, which abut along a verticalcentral longitudinal engine plane 36 (see Figs. 1 and 2), and said planelies substantially midway between the cylinders 12 of one bank and thecylinders of the other bank, and further, said plane contains thecrankshaft axis 35. It is noted that the end wall of the gear casestructure carries bearings for said engine crankshaft and other shafts,and also carries lubricating ducts 36 of suitable design. The interiorof the gear case houses the necessary accessory drive mechanism such asgears 37, and that such gears may be substantially disposed in a commontransverse engine plane.

The two integral casings lilo-11a and Rib-11b are secured or boltedtogether in any suitable manner, the casings having a flange 31 whichsupports the bolts 32 and where convenient, certain transverse bolts 33are utilized to secure said casings together, to form the completeassembly.

It will be apparent to those skilled in the art to which my inventionpertains that various changes and modifications may be made hereinwithout departing from the spirit of my invention or from the scope ofthe appended claims.

I claim:

1. An integral crankcase and accessory case structure for amulti-cylinder internal combustion engine for aircraft having aplurality of aligned engine cylinders and a crankshaft supported by saidstructure, said crankcase and accessory case structure comprising a pairof separate casing portions having complementary abutting facingsmeeting a central vertical longitudinal engine plane containing thecrankshaft axis, each of said casing portions including a crankcase partand an integral accessory part at one end of the crankcase part andextending upwardly above the topmost rim of the said crankcase part, andaccessory drive mechanism housed within said accessory casing part andextended into said upwardly extending portion for driving connectionwith accessories mounted on the front and rear faces of said upwardlyextending portion of said accessory casing part and disposed to extendsubstantially parallel to said vertical ccntral longitudinal engineplane.

2. An integral crankcase and accessory case structure for amulti-cylinder internal combustion engine for aircraft having aplurality of aligned engine cylinders and a crankshaft supported by saidstructure, said crankcase and accessory case structure comprising a pairof separate casing portions having complementary abutting facingsmeeting in a central vertical longitudinal engine plane containing thecrankshaft axis, each of said casing portions including a crankcase partand an integral accessory part at one end of the crankcase part andextend-- ing upwardly above the topmost rim of the said crankcase part,and accessory drive mechanism housed within said accessory casing partand extended into said upwardly extending portion for driving connectionwith accessories mounted on the front and rear faces of saidupwardlyextending portion of said accessory casing part and disposed toextend substantially parallel to said vertical central longitudinalengine plane, said casing portions illeluding flanges extendinglongitudinally along the upper edge of the crankcase part and along theadjacent face only of said accessory casing part, and means bolting saidflanges together.

3. An integral crankcase an accessory case structure for amulti-cylinder internal combustion engine for aircraft having aplurality of aligned engine cylinders and a crankshaft supported by saidstructure, said crankcase and accessory case structure comprising a pairof separate casing portions having complementary abutting facingsmeeting in a central vertical longitudinal engine plane containing thecrankshaft axis, each of said casing portions including a crankcase partand an. integral accessory part at one end of the crankcase part andextending upwardly above the topmost rim of the said crankcase part, andaccessory drive mechanism housed within said accessory casing part andextended into said upwardly extending portion for driving connectionwith accessories mounted on the front and rear faces of said upwardlyextending portion of said accessory casing part and disposed to extendsubstantially parallel to said vertical central longitudinal engineplane, said casing portions including flanges extending longitudinallyalong the upper edge of the crankcase part and along the adjacent faceonly of said accessory casing part, and means bolting said flangestogether, and other means extending transversely through the accessorycasing remote from said crankcase part to further secure said separatecasings together.

4. A crankcase and gear case assembly for an aircraft internalcombustion engine comprising a pair of integral L-shaped casings securedtogether along a ver tical longitudinal central engine plane, one leg ofeach casing providing a crankcase part and said other leg providing agear casing part extending above the topmost rim of said crankcase part.

5. A crankcase and gear case assembly for an aircraft internalcombustion engine comprising a pair of integral L-shaped casings securedtogether along a vertical longitudinal central engine plane, one leg ofeach casing providing a crankcase part and said other leg providing agear casing part and provided with a substantially continuous transversewall comprising the front wall of the gearcase part and a division wallseparating the crankcase from said gear case.

6. A crankcase and gear case assembly for an aircraft internalcombustion engine comprising a pair of integral L-shaped casings securedtogether along a vertical longitudinal central engine plane, one leg ofeach casing providing a crankcase part and said other leg providing agear casing part, the interior of said casings having a verticaltransverse Wall portion providing a substantially continuous transversewall comprising the front wall of the gear case part and a division wallseparating the crankcase from said gear case, the front and rear wallsof said accessory gear casing providing a mounting for accessories, saidaccessory mounting immediately adjacent to said crankcase partsupporting the accessory to overlay said crankcase portion.

7. A crankcase and gear case assembly for an aircraft internalcombustion engine comprising a pair of integral L-shaped casings securedtogether along a vertical longitudinal central engine plane, one leg ofeach casing providing a crankcase part and said other leg providing agear casing part, the interior of said casings having a verticaltransverse wall portion providing a substantially continuous transversewall comprising the front Wall of the gear case part and a division wallseparating the crankcase from said gear case, the front and rear wallsof said accessory gear casing providing a mounting for accessories, saidaccessory mounting on said front wall supporting the accessory tooverlay said crankcase portion, said accessory mountings disposed oneither side of the dividing vertical longitudinal central plane of thesaid crankcase and gear case assembly.

8. A crankcase and gear case assembly for an internal combustion enginehaving horizontally disposed aligned cylinders and a crankshaftcomprising two integral L- shaped half casings secured together along avertical longitudinal medial engine plane containing the crankshaft,said two half casings comprising substantially symmetrical andcomplementary crankcase and gear case structures each provided with ahorizontally extending crankcase part for supporting said cylinders anda vertically extending gear case part extending above the topmost rim ofthe crankcase part.

'9. A crankcase and gear case assembly for an internal combustion enginecomprising two integral generally L-shaped half casings secured togetheralong a vertical longitudinal medial engine plane, said two half casingscomprising substantially symmetrical and complementary longitudinallyextending crankcase and vertically extending gear case parts, andprovided with integral complementary end walls and an intermediate walldividing the crankcase and gear case, said intermediate wall disposed ina transverse vertical engine plane containing the front wall of saidgear case part.

References Cited in the file of this patent UNITED STATES PATENTS2,019,558 Brush Nov. 5, 1935 2,025,297 Meyer Dec. 24, 1935 2,172,100Hoffman et al. Sept. 5, 1939 2,397,434 Ricart Mar. 26, 1946 2,439,472Jackson Apr. 13, 19-18 2,515,347 Jameson July 18, 1950 2,678,037 Wiegmanet al May 11, 1954

